I believe that if the motor is operating within spec., even when it is stalled, it won't draw enough current to blow the fuse; generally 10 or 15 amps. So, is it one window that blows the fuse or any window? If it is only one window, it's probably a bad motor in that window regulator. If it is any window, that blows the fuse then it may be wiring or a bad switch. Connectors in doors sometimes get wet and corrode. Some cars, like the 129 SL's have memory windows and then it really gets complicated. But if the motor is running freely ( out of vehicle ), I've measured them in my R129 at 2 to 3 amps. My windows were binding due to dried up and hardened grease. Re-lubricating solved my blowing fuse issue.

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